refactor: nettests is now an internal package (#165)

I'm moving everything into internal packages since this ain't a library.

While there, remove typo that was causing a build breakage.

nettests/ndt.go

@@ -1,83 +0,0 @@
-package nettests
-
-import (
-	"github.com/pkg/errors"
-)
-
-// NDT test implementation. We use v7 of NDT since 2020-03-12.
-type NDT struct {
-}
-
-// Run starts the test
-func (n NDT) Run(ctl *Controller) error {
-	// Since 2020-03-18 probe-engine exports v7 as "ndt".
-	builder, err := ctl.Session.NewExperimentBuilder("ndt")
-	if err != nil {
-		return err
-	}
-	return ctl.Run(builder, []string{""})
-}
-
-// NDTTestKeys for the test
-type NDTTestKeys struct {
-	Upload         float64 `json:"upload"`
-	Download       float64 `json:"download"`
-	Ping           float64 `json:"ping"`
-	MaxRTT         float64 `json:"max_rtt"`
-	AvgRTT         float64 `json:"avg_rtt"`
-	MinRTT         float64 `json:"min_rtt"`
-	MSS            float64 `json:"mss"`
-	RetransmitRate float64 `json:"retransmit_rate"`
-	IsAnomaly      bool    `json:"-"`
-}
-
-// GetTestKeys generates a summary for a test run
-func (n NDT) GetTestKeys(tk map[string]interface{}) (interface{}, error) {
-	var err error
-	testKeys := NDTTestKeys{IsAnomaly: false}
-
-	summary, ok := tk["summary"].(map[string]interface{})
-	if !ok {
-		return testKeys, errors.New("summary key is invalid")
-	}
-
-	// XXX there is likely a better pattern for this
-	testKeys.Upload, ok = summary["upload"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "upload key invalid")
-	}
-	testKeys.Download, ok = summary["download"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "download key invalid")
-	}
-	testKeys.Ping, ok = summary["ping"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "ping key invalid")
-	}
-	testKeys.MaxRTT, ok = summary["max_rtt"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "max_rtt key invalid")
-	}
-	testKeys.AvgRTT, ok = summary["avg_rtt"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "avg_rtt key invalid")
-	}
-	testKeys.MinRTT, ok = summary["min_rtt"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "min_rtt key invalid")
-	}
-	testKeys.MSS, ok = summary["mss"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "mss key invalid")
-	}
-	testKeys.RetransmitRate, ok = summary["retransmit_rate"].(float64)
-	if !ok {
-		err = errors.Wrap(err, "retransmit_rate key invalid")
-	}
-	return testKeys, err
-}
-
-// LogSummary writes the summary to the standard output
-func (n NDT) LogSummary(s string) error {
-	return nil
-}